get exprs from AffyBatch
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@james-w-macdonald-5106
Last seen 11 hours ago
United States
I'm not exactly sure what you are trying to do here, but I am going to assume that you want to compute expression values for your genes, and then export to a file. The AffyBatch contains your raw PM and MM data, not expression values. When you do exp <- exprs(myAffyBatch) You are simply creating a matrix of PM and MM values. To compute expression values, you want to do something like eset <- rma(myAffyBatch) see also ?expresso and ?mas5 for other ways to compute expression values. Once you have run rma or whatever, you have an exprSet that can be used with write.exprs() to export. Note that the function you want is write.exprs() not exprs.write(). In addition, you only have to pass the variable name of your exprSet and the filename. I don't know if you actually used file=** and sep=*, but you don't need sep (default is "\t", which is fine for most uses), and file=** will give you a syntax error. You need something like file="Expression values.txt" HTH, Jim James W. MacDonald Affymetrix and cDNA Microarray Core University of Michigan Cancer Center 1500 E. Medical Center Drive 7410 CCGC Ann Arbor MI 48109 734-647-5623 >>> Hao Liu <liuha@umdnj.edu> 02/04/04 12:29AM >>> I tried to use exprs to get expset by > exp <- exprs(myAffyBatch) I then tried to write: exprs.write(exp,file=**,sep=*) however, I can't do this, seems exp is not really a expset object. Best regards Hao Liu, Ph. D _______________________________________________ Bioconductor mailing list Bioconductor@stat.math.ethz.ch https://www.stat.math.ethz.ch/mailman/listinfo/bioconductor
Microarray Cancer Microarray Cancer • 1.3k views
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@rafael-a-irizarry-205
Last seen 10.2 years ago
i would like to add to jim's suggestion that there is also exprs2excel (myAffyBatch) for creation of excel compatible files. On Wed, 4 Feb 2004, James MacDonald wrote: > I'm not exactly sure what you are trying to do here, but I am going to > assume that you want to compute expression values for your genes, and > then export to a file. > > The AffyBatch contains your raw PM and MM data, not expression values. > When you do > > exp <- exprs(myAffyBatch) > > You are simply creating a matrix of PM and MM values. To compute > expression values, you want to do something like > > eset <- rma(myAffyBatch) > > see also ?expresso and ?mas5 for other ways to compute expression > values. Once you have run rma or whatever, you have an exprSet that can > be used with write.exprs() to export. > > Note that the function you want is write.exprs() not exprs.write(). In > addition, you only have to pass the variable name of your exprSet and > the filename. I don't know if you actually used file=** and sep=*, but > you don't need sep (default is "\t", which is fine for most uses), and > file=** will give you a syntax error. You need something like > file="Expression values.txt" > > HTH, > > Jim > > > > James W. MacDonald > Affymetrix and cDNA Microarray Core > University of Michigan Cancer Center > 1500 E. Medical Center Drive > 7410 CCGC > Ann Arbor MI 48109 > 734-647-5623 > > >>> Hao Liu <liuha@umdnj.edu> 02/04/04 12:29AM >>> > I tried to use exprs to get expset by > > > exp <- exprs(myAffyBatch) > > I then tried to write: > > exprs.write(exp,file=**,sep=*) > > however, I can't do this, seems exp is not really a > expset object. > > > > Best regards > > Hao Liu, Ph. D > > _______________________________________________ > Bioconductor mailing list > Bioconductor@stat.math.ethz.ch > https://www.stat.math.ethz.ch/mailman/listinfo/bioconductor > > _______________________________________________ > Bioconductor mailing list > Bioconductor@stat.math.ethz.ch > https://www.stat.math.ethz.ch/mailman/listinfo/bioconductor >
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I got this message using mas5: mascolon <- mas5(myAffyBatch,normalize=TRUE, sc=150, analysis="ablolute"); background correction: mas PM/MM correction : mas expression values: mas background correcting...Error: cannot allocate vector of size 585042 Kb My AffyBatch has 151 samples, could this be the problem? Thanks a lot for your kind replies. Best Hao -----Original Message----- From: Rafael A. Irizarry [mailto:ririzarr@jhsph.edu] Sent: 2004??2??4?? 11:18 To: James MacDonald Cc: bioconductor@stat.math.ethz.ch; liuha@umdnj.edu Subject: Re: [BioC] get exprs from AffyBatch i would like to add to jim's suggestion that there is also exprs2excel (myAffyBatch) for creation of excel compatible files. On Wed, 4 Feb 2004, James MacDonald wrote: > I'm not exactly sure what you are trying to do here, but I am going to > assume that you want to compute expression values for your genes, and > then export to a file. > > The AffyBatch contains your raw PM and MM data, not expression values. > When you do > > exp <- exprs(myAffyBatch) > > You are simply creating a matrix of PM and MM values. To compute > expression values, you want to do something like > > eset <- rma(myAffyBatch) > > see also ?expresso and ?mas5 for other ways to compute expression > values. Once you have run rma or whatever, you have an exprSet that > can be used with write.exprs() to export. > > Note that the function you want is write.exprs() not exprs.write(). In > addition, you only have to pass the variable name of your exprSet and > the filename. I don't know if you actually used file=** and sep=*, but > you don't need sep (default is "\t", which is fine for most uses), and > file=** will give you a syntax error. You need something like > file="Expression values.txt" > > HTH, > > Jim > > > > James W. MacDonald > Affymetrix and cDNA Microarray Core > University of Michigan Cancer Center > 1500 E. Medical Center Drive > 7410 CCGC > Ann Arbor MI 48109 > 734-647-5623 > > >>> Hao Liu <liuha@umdnj.edu> 02/04/04 12:29AM >>> > I tried to use exprs to get expset by > > > exp <- exprs(myAffyBatch) > > I then tried to write: > > exprs.write(exp,file=**,sep=*) > > however, I can't do this, seems exp is not really a > expset object. > > > > Best regards > > Hao Liu, Ph. D > > _______________________________________________ > Bioconductor mailing list > Bioconductor@stat.math.ethz.ch > https://www.stat.math.ethz.ch/mailman/listinfo/bioconductor > > _______________________________________________ > Bioconductor mailing list > Bioconductor@stat.math.ethz.ch > https://www.stat.math.ethz.ch/mailman/listinfo/bioconductor >
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